[Value of venous ultrasonic tomography in the screening for unusual emboli-causing foci]

In certain cases of pulmonary embolism, phlebography of the lower extremities remains normal. The study of 219 consecutive cases of pulmonary embolism shows the advantage of venous ultrasonic tomography which, alone, enables to screen the embolic focus in 10% of the cases, either because the phlebographic data are insufficient (5%), or because the embolic focus cannot be reached with phlebography (5%), especially in deep femoral and internal saphenous thromboses. On the other hand, popliteal venous aneurysms, which represent 1% of all embolic foci in this study, are always discovered by ultrasonography. Therefore this technique appears absolutely necessary for the diagnosis of an embolic venous focus.